CN101611402B - System and method for optimizing changes of data sets - Google Patents

Abstract

A system and method for generating an update data set to be sent to remote terminals. The update data set comprises operators describing differences between two data sets, so that a remote terminal is able to transform an old data set into a more recent data set. The system comprising a comparator for comparing data elements in the data sets, and a selector for selecting operators based on a change parameter stored in a memory.

Description

Systems and methods for optimizing changes in datasets

technical field

The present invention relates to the dissemination of data in a computer environment, and in particular the invention relates to extracting changes in data sets for distributing these changes in a computer network.

Background technique

Sending data over computer networks is very common these days. Due to technological advances, the amount of data being sent has grown rapidly, making it possible to send and process more data at higher speeds than before. In addition, new applications require more data, as these new applications become more complex. An example of a computer system where data dissemination technology is one of the most important parts is an electronic trading system.

Electronic trading of securities, derivatives, commodities, and other financial instruments results in vast amounts of data that must be distributed to users who need the data to make trading decisions, statistical calculations, and other evaluations. The process of extracting and sending all this information in a high-performance computer system is very demanding on the processor. The amount of CPU time is a scarce resource and should not be wasted on execution steps that could have been avoided.

Furthermore, users connecting to such a central transaction system typically want to have information as quickly as possible. In these cases, it may not be sufficient to increase the performance of the central system by, for example, updating hardware.

In order to get rid of bottlenecks or other potential problems in the system, additional techniques must be used.

Therefore, one such additional technique is to make the processor work more efficiently. For example, when updating a data set on a user terminal, there are different methods.

A commonly used and obvious solution is to always send a brand new dataset replacing the old dataset. This is often inefficient when only a portion of the data in the dataset has changed. Therefore a more efficient way may be to send only the part of the dataset that has changed. A further improvement is to send delta changes.

Another known technique is to send an operator describing the difference between two datasets. Applying the operator to a first data set can transform the first data set into a second data set.

Optimization is possible by choosing a good set of operators to operate on the dataset. Today, the methods available for extracting differences in datasets are insufficient. Therefore, there is a need to develop techniques for extracting and selecting operators in an efficient manner - eg by fewer steps - in order to reduce the load on the processor, and for reducing data propagation, such as bandwidth, in computer systems.

Contents of the invention

Therefore, the present invention aims to provide a solution for generating an update data set to be sent to a remote terminal.

Another object of the present invention is to provide a solution for efficiently extracting data from a data set.

Another object of the present invention is to provide a solution that efficiently extracts and/or selects operators based on differences between datasets.

Another object of the invention is to provide a solution for generating a data structure to be sent to a remote terminal.

Another object of the invention is to provide a solution that uses less processor time.

According to a first aspect of the present invention, the above objects and others are achieved by a computer system for generating an updated data set to be transmitted to a remote terminal, the updated data set comprising a first data set describing elements containing classification data and containing An operator for the difference between the second data set of categorical data elements, the computer system comprising:

- a memory comprising the first data set and the second data set,

- a comparator, which can be connected to the memory for sequentially comparing the data elements in the second data set with the data elements in the first data set, the result of the first comparison controlling which data element in the first data set is compared with the data elements in the first data set Which data elements in the two data sets are to be compared in the second comparison, after each comparison the change parameters in the memory are updated, and when it is detected that the data elements in the second data set are consistent with the data elements in the first data set launch picker,

a said selector, the selector is connectable to the memory and the comparator, the selector is used to determine the operator based on the variable parameters stored in the memory, and to store the determined operator in the memory,

This results in an updated data set to be sent to the remote terminal comprising an operator describing the difference between the first data set and the second data set.

The computer system has the advantage that it enables a computer system such as a transaction system to more efficiently generate update data sets by using less CPU time. For example, this is because the computer system allows a first data set and a second data set to be compared by running each data set through only one pass.

The computer system further includes a communicator associated with the selector for generating and sending an update message including the updated data set. The message may include a data structure, such as a list, array, bitboard, stack, heap, tree, or set, etc., that includes the data set to be sent to the remote terminal. Preferably, the message is sent using the FIX standard, however any other protocol known to those skilled in the art may be used to send the message, such as Omnet API, XTP, SSL or any other standard or proprietary protocol.

Preferably, the first data set and the second data set include dynamic data elements that change over time. For example, the first data set may be the order book in the trading system at time T1, and the second data set may be the order book at time T2. The data in the order book may have changed between times T1 and T2 because new orders to buy or quotes for the sale financial instrument may have entered. The information dissemination system may disseminate information to remote terminals at certain predetermined time intervals or based on activity in the command book. For example, if the command book has not received any new commands, it does not make sense to send a new update to the remote terminal. However, when new commands enter the command book, new information must be propagated to the remote terminal. Therefore, it may be necessary to send update messages when activity occurs at this point in time. Another example where changes may occur in the command book is during state transitions, such as when the command book is opened or closed.

Thus, the second data set is a later version of the first data set. This way, the central system can compare what has changed, and since the central system knows what data sets the remote terminals have, it can extract operators to store and send to the update data set. In addition, a specific portion of the variation between the first data set and the second data set may also be sent to a specific remote terminal, since a user at a remote terminal may wish to obtain information related to a different portion of the data set.

Preferably, the operator is determined from the group comprising the following operators: add operator, delete operator, replace operator. By determining these operators based on the changing parameters, an updated data set can be generated. These operators can be combined as described later in this document.

The variation parameters preferably comprise a first counter associated with the first data set and a second counter associated with the second data set. In this way, the selection process can be monitored and managed in a more accurate manner. Accordingly, the selector may determine an operator based on a relationship between a first counter associated with a first data set and a second counter associated with a second data set. This speeds up the selection process, since the relation is preferably a relation selected from a set of relations comprising: >, <, =, ≥, ≤ or ≠. Based on the relationship between the counters, at least one operator can be determined: add, delete, replace.

The variation parameters may further include a first position parameter associated with the first data set and a second position parameter associated with the second data set for tracking the logical position of the comparator in the first data set and the second data set . In this way, the result of the sequential comparison between the first list and the second list can be monitored and managed in a more accurate manner.

Operators can include delta changes. Thus, if only a portion of the data elements has changed, this operator can describe the portion of the data elements that have changed. However, the operator may also describe that an entire data element should be deleted or replaced or added, for example.

Each data element normally includes at least a key (key). However, a data element may also include a data portion. Generally, the data section can be empty. In a trading system, however, the typical key is the price in the order book. The data portion may eg be the total capacity for that price. However, if the key includes price and time, it is not always necessary to send the entire key. Data element classification can be based on price and time, but only price can be sent to the remote terminal.

In a second aspect of the invention, the above objects and others are achieved by an electronic transaction system comprising a computer system as described above.

Therefore, in the electronic trading system, the computer system can be an integrated module. The computer system can also be an independent module sold separately as an information retrieval system.

In a third aspect of the invention, the above objects and others are achieved by a method for generating an updated data set to be sent to a remote terminal, the updated data set comprising a description of a first data set containing classified data elements and a first data set containing classified data An operator for the difference between a second dataset of elements, the method comprising the steps of:

- sequentially compare the data elements in the first data set with the data elements in the second data set, the result of the first comparison controls which data element in the first data set and which data element in the second data set will be in the second data set compared in the second comparison,

- after each comparison, the changed parameters are updated in memory,

- upon detection that a data element in the second data set coincides with a data element in the first data set, initiating a selection process which determines an operator on the basis of varying parameters stored in memory,

- Storing the determined operator in a memory, resulting in an updated data set to be sent to the remote terminal, the updated data set comprising the operator describing the difference between the first data set and the second data set.

This method has the advantage that it enables a computer system such as a trading system to generate update data sets more efficiently by using less CPU time, since the invention, for example, allows each data set to be updated by running each data set only once from start to finish. A comparison can be made between the first data set and the second data set.

The method may further comprise the step of comparing the data elements in association with the determined operator. This way, the system can keep track of which data element the operator should be applied to.

The method may also include the step of determining at least one operator from the group consisting of the following operators: add operator, delete operator, replace operator. By determining these operators based on changing parameters an updated data set can be generated. These operators can be combined as described below in this document.

As mentioned above, the variation parameters may include a first counter associated with the first data set and a second counter associated with the second data set. Accordingly, the method may further comprise the step of determining the operator based on the relationship between the first counter associated with the first data set and the second counter associated with the second data set.

Preferably, each data element comprises a key and a data portion, the method may further comprise combining at least one of the key and the data portion of the data elements of the first data set with at least one of the key and the data portion of the data elements of the second data set A step for comparison.

As mentioned earlier, the first data set and the second data set may include dynamic information that changes over time.

In a fourth aspect of the present invention, the above objects and others are achieved by a computer program product according to any one of the preceding aspects and/or embodiments, stored on a data carrier.

These and other aspects of the invention will be apparent from and explained with reference to the embodiments described hereinafter.

Description of drawings

Figure 1 shows an overview of a computer network in which the invention can be used.

Figure 2 shows an electronic device comprising a memory, a first data set, a second data set, a variation parameter, a comparator, a selector, an update data set and an interface.

Figure 3 shows a data set including data elements, and data elements including keys and data.

Figure 4 shows the algorithm used to iterate the dataset described in the text.

Figure 5 shows dataset A and dataset B.

Figure 6 shows a comparison of data elements in data set A with data elements in data set B.

Figure 7 shows a comparison of data elements in data set A with data elements in data set B.

FIG. 8 shows a comparison of data elements in data set A and data elements in data set B. FIG.

FIG. 9 shows a comparison of data elements in data set A with data elements in data set B. FIG.

FIG. 10 shows a comparison of data elements in data set A with data elements in data set B. FIG.

Fig. 11 shows the first operator selected by the selection method.

FIG. 12 shows a comparison of data elements in data set A with data elements in data set B. FIG.

FIG. 13 shows a comparison of data elements in data set A with data elements in data set B. FIG.

FIG. 14 shows a comparison of data elements in data set A with data elements in data set B. FIG.

FIG. 15 shows a comparison of data elements in data set A with data elements in data set B. FIG.

FIG. 16 shows a comparison of data elements in data set A with data elements in data set B. FIG.

FIG. 17 shows a comparison of data elements in data set A and data elements in data set B. FIG.

Fig. 18 shows additional operators selected by the selection method.

Fig. 19 shows an update data set including operators selected by a selection method.

FIG. 20 shows Dataset A and Dataset B before operators are used.

Figure 21 shows updating a row in a data set.

Fig. 22 shows the change of data set A after applying the first operator.

Figure 23 shows updating a row in a data set.

Fig. 24 shows the change of the data set A after applying the second operator.

Figure 25 shows updating a row in a data set.

Fig. 26 shows the change of the data set A after applying the third operator.

Figure 27 shows updating a row in a data set.

Fig. 28 shows the change of the data set A after applying the fourth operator.

Figure 29 shows the result after applying the operator to dataset A.

FIG. 30 shows selection method B.

Detailed ways

FIG. 1 shows a computer network comprising a remote terminal 1 , a central computer 2 and a gateway or router 3 . Between the different devices there are connections shown by lines 4 with different thicknesses. The thickness indicates bandwidth (data rate). Thick lines have a high data rate, while thin lines have a low data rate. The 3 front-end computers in Fig. 1 have letters on the screen, which means that the front-end computers are remote terminals belonging to users A, B and C. The update data set 6 is sent from the central computer 2 to the remote terminal 1 through a network comprising lines 4 and network devices such as routers or the like. The update data set 6 is generated in the computer system 5 according to the invention.

Figure 2 shows a computer system 5 according to the invention. The computer system 5 comprises a memory 10 , a comparator 14 , a selector 15 and an interface 16 for sending the update data set 7 . The memory 10 comprises a first data set 11 and a second data set 12 . Furthermore, the memory comprises an area for storing variation parameters 13 , an area for storing update data sets 7 and an area for storing operators 18 .

FIG. 3 shows a data set 11 and a magnified portion of a data element 17 in the data set. In this figure, a data element 17 includes both a key and a data portion. However, in another embodiment of the invention, the data element 17 may include at least a key portion.

In the following, the present invention will be explained in detail with reference to the accompanying drawings. Details of how an operator can be decided/selected will be explained.

Below is an example of a method for selecting an operator that describes the difference between two data sets in an efficient manner.

A dataset consists of one or several data elements, where each data element has a key and possibly a data part. The key, together with the classification algorithm, gives each data element its logical position in the data set.

The method is based on:

(1) Design an effective operator set.

(2) Design efficient algorithms to evaluate the differences between two data sets, and use sets of operators to describe these differences. To achieve this, the algorithm uses one-pass traversing over the two datasets.

This method uses the following set of operators to describe changes between two datasets:

method introduction

Data elements that are consistent in both data sets (both key and data parts) are unchanged. The algorithm considers unchanged data elements as barriers. This method uses barriers to determine when optimizations on operators can be performed. The method is based on the observation that operators used before barriers are detected can be optimized.

Assuming data sets A and B, see Figure 5. From dataset A, several operators can be applied to implement dataset B. The algorithms and methods described below extract these operators that transform dataset A into dataset B.

During traversal of the dataset, the following counters #Del and #Add are preferably used. These counters are initially set to 0 or any other corresponding value that satisfies the same goal.

Dataset A and Dataset B are then traversed, preferably from the beginning, according to the sort command of the key.

The actual logical position in dataset A is referred to below as APos, which includes the position parameter for dataset A. The actual logical position in dataset B is referred to below as BPos, which includes the location parameter for dataset B. APos and BPos are initially set as the first logical positions in datasets A and B.

initialization:

Set #Add=0 and #Del=0.

Set APos and BPos to the first logical position in datasets A and B.

Set APosStart=APos and BPosStart=BPos.

Algorithm: Iterate data sets A and B, and calculate #Add and #Del:

1. Compare the set A data element at logical location APos with the set B data element at logical location BPos.

a. If there is no A data element and B data element, use method B below to select the operator, and then proceed to step 2 (Done).

b. If the keys are the same, but the data parts are different, add 1 to #Add, add 1 to #Del, add 1 to APos, and add 1 to BPos. Proceed to step 1 and compare the next data element.

c. If the key of the A data element (according to the sort command) is worse than the key of the B data element, or there is no A data element, then increment #Add and BPos. Proceed to step 1 and compare the next data element.

d. If the A data element has a better key (according to the sort command) than the B data element key, or if there is no B data element, increment #Del and APos. Proceed to step 1 and compare the next data element.

e. If both the key and data parts agree, the barrier has been found. If (#Add≠0 or #Del≠0), use method B below to select an operator. continue:

Set #Add=0 and #Del=0.

Increment APos by 1 and increase BPos by 1.

Set APosStart=APos and BPosStart=BPos.

Proceed to step 1 and compare the next data element.

2. Done

Method B. Selection operator: compares #Del to #Add.

a. If #Del > #Add, select the following operators:

Delete (N=#Del) operator at logical location APosStart.

followed by:

#Add addition operators from the elements of the B set, starting at the logical position APosStart.

b. If #Del = #Add, select the following operators:

#Add replacement operators from set B elements, starting at logical position APosStart.

c. If #Del<#Add, select the following operators:

#Del replacement operators from set B elements, starting at logical position APosStart.

followed by:

(#Add-#Del) addition operators from elements of set B, starting from APosStart+#Del.

example

Below is an example describing the steps of the different methods with reference to the figures.

According to the table shown in Fig. 5, imagine two data sets A and B. Data elements are preferably sorted based on key, resulting in the highest value at logical position 1. Dataset A represents the old dataset and Dataset B represents the new dataset. The task is to transform dataset A into dataset B.

Execution of the method:

initialization:

Set #Add=0 and #Del=0.

Set APos at the first logical position in dataset A, set BPos at the first logical position in dataset B,

Apos=1 and Bpos=1 are given.

Set APosStart=APos and BPosStart=BPos,

AposStart=1 and BPosStart=1 are given.

The method and system begin by initializing a counter, which is preferably used during iteration over a data set.

Then an iterative step begins where the variable parameters #Add and #Del are iterated and incremented.

Step 1. Compare the data elements of set A with the data elements of set B. Since both Apos and Bpos are set to 1, this means that the first element in the list is compared. However, if the data elements in the data set are classified in another way, the method may start comparing other data elements first.

This comparison is depicted in FIG. 6 . In this case, 99 is worse than 101 (see algorithm step c) (elements in dataset A (Apos=1) are worse than elements in dataset B (Bpos=1), so #Add is incremented by 1, assuming that #Add=1. Add 1 to BPos, assuming that BPos=2.

Continue with step 1 in the algorithm and compare the next data element.

Step 2. Compare the data elements of set A with the data elements of set B. Now the Bpos counter has been incremented by 1, so the data element at (Apos=1) in dataset A is compared with the data element at (Bpos=2) in dataset B.

This comparison is shown in FIG. 7 . 99 is worse than 100 (see algorithm step c), so #Add is incremented by 1, assuming #Add=2. Add 1 to BPos, assuming that BPos=3.

Continue with step 1 in the algorithm and compare the next data element.

Step 3. Compare the data elements of set A with the data elements of set B. Similar to the steps above.

This comparison is shown in FIG. 8 . 99 is better than 97 (see algorithm step d), so #Del is incremented by 1, assuming #Del=1. Add 1 to APos, assuming Apos=2.

Continue with step 1 in the algorithm and compare the next data element.

Step 4. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 9 . 98 is better than 97 (see algorithm step d), so #Del is incremented by 1, assuming #Del=2. Add 1 to APos, assuming Apos=3.

Continue with step 1 in the algorithm and compare the next data element.

Step 5. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 10 . Both key and data parts are the same (see algorithm step e), so the barrier has been reached.

Use method B to fire up the picker and select the operator.

Step 6. Compare #Del with #Add. According to method B, step b can be applied in this case:

(b) #Del(2)=#Add(2) and thus select the following operators:

Replace 2(#Add) operator, select data from set B, start from logical position AposStart=1.

The selected operators are shown in FIG. 11 .

Step 7. The iteration and comparison of the data elements in dataset A and dataset B continues.

Set #Add=0 and #Del=0.

To reach the barrier the counter is incremented, APos is incremented and BPos is incremented by 1, assuming Apos=4 and Bpos=4.

Set APosStart=APos and BPosStart=BPos, assuming APosStart=4 and BPosStart=4.

Continue with step 1 in the algorithm and compare the next data element.

Step 8. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 12 . 96 is better than 93 (see algorithm step d), so #Del is incremented by 1, assuming #Del=1. Add 1 to APos, assuming APos=5.

Continue with step 1 in the algorithm and compare the next data element.

Step 9. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 13 . 95 is better than 93 (see algorithm step d), so #Del is incremented by 1, assuming #Del=2. Add 1 to APos, assuming that APos=6.

Continue with step 1 in the algorithm and compare the next data element.

Step 10. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 14 . 94 is better than 93 (see algorithm step d), so #Del is incremented by 1, assuming #Del=3. Add 1 to APos, assuming that APos=7.

Continue with step 1 in the algorithm and compare the next data element.

Step 11. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 15 . The keys are the same, but the data part is different (10 is not equal to 15) (see algorithm step b).

#Add is incremented by 1, assuming that #Add=1.

Add 1 to #Del, assuming #Del=4.

Add 1 to APos, assuming APos=8.

Add 1 to BPos, assuming that BPos=5.

Continue with step 1 in the algorithm and compare the next data element.

Step 12. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 16 . There is no B data element (empty) (see algorithm step d).

Add 1 to #Del, assuming #Del=5. Add 1 to Apos, assuming that APos=9.

Continue with step 1 in the algorithm and compare the next data element.

Step 13. Compare the data elements of set A with the data elements of set B. This comparison is shown in FIG. 17 . The element at APos(9) in dataset A and the element at BPos(5) in dataset B are empty, so step a in the algorithm is applied. Step a in the algorithm activates the selector, so method B as described in step 14 applies.

After this selection proceed to step 2 (Finish).

Step 14. By using selection method B, compare counter #Del with counter #Add.

According to selection step (a) in selection method B, #Del(5)>#Add(1), so it is preferable to select the operator as follows:

Delete 5 (#Del) operator at logical location APosStart(4).

followed by:

Add 1 (#Add) operator from set B data element, starting from logical position APosStart(4).

The selected operators are shown in FIG. 18 .

Step 15. The last step 2 (Completion) in the algorithm is implemented in step 14 as described above.

After completion of iterations of the algorithm and method B, the full number of operators describing the change from dataset A to dataset B is stored in memory, preferably together with the corresponding logical locations, keys and data parts. An update data set including operator, logical location, key and data parts is generated as shown in FIG. 19 .

In another embodiment, logical locations may be represented by keys. In this case, the terminal receiving the updated data set preferably includes information on how the logical positions are related to each other in order to be able to classify the data elements. Therefore, the logical position does not have to be 1, 2, 3...etc. It can also be represented by A, B, C... and so on, as long as the positions are related to each other to facilitate classification.

Using the knowledge of the data set A and the updated data set including the operators as shown in FIG. 19 , the data set B can be generated by sequentially using one operator at a time from the beginning to the end.

A step-by-step method description of how to do this is shown below using Figures 20-29.

FIG. 20 shows the data set A and the data set B before the update data set is applied to the data set A. Therefore, the following steps generate dataset B from dataset A by using the updated dataset in Figure 19.

By applying the first row of the updated data set in FIG. 19 shown in FIG. 21 to data set A, a modified data set A as shown in FIG. 22 is obtained.

By applying the second row of the updated data set in FIG. 19 shown in FIG. 23 to data set A, a modified data set A as shown in FIG. 24 is obtained.

By applying the third row of the updated data set in FIG. 19 shown in FIG. 25 to data set A, a modified data set A as shown in FIG. 26 is obtained.

By applying the fourth row of the updated data set in FIG. 19 shown in FIG. 27 to data set A, a modified data set A as shown in FIG. 28 is obtained.

As shown in FIG. 29, the operator has now transformed Data Set A into Data Set B.

In the above description, the term "comprising" does not exclude other data elements or steps, and "a" does not exclude a plurality.

Furthermore, the term "comprising" does not exclude other data elements or steps.

Claims (12)

1. A computer system for generating an updated data set to be sent to a remote terminal, the updated data set including a difference between a first data set containing classified data elements and a second data set containing classified data elements operator determined from the group consisting of the following operators: addition operator, deletion operator, replacement operator, The computer system includes: a memory comprising a first data set and a second data set, A comparator connected to the memory for sequentially comparing data elements in the second data set with data elements in the first data set, wherein a data element in the second data set is compared with a data element in the first data set The result of the first comparison between elements controls which element in the first dataset will be compared with which element in the second dataset in the second comparison in that element's comparison order, after each comparison updating change parameters in the memory, and activating the selector when it is detected that the data elements in the second data set are consistent with the data elements in the first data set, wherein the change parameters include the first counter associated with the first data set and the The second counter associated with the second data set also includes a first position parameter associated with the first data set and a second position parameter associated with the second data set, for comparing the comparator between the first data set and the second data set centralized location for tracking, a said selector connected to a memory and a comparator for determining an operator based on a variable parameter stored in the memory and storing the determined operator in the memory, This results in an updated data set to be sent to the remote terminal comprising an operator describing the difference between the first data set and the second data set. 2. The computer system of claim 1, further comprising a communicator associated with the selector for generating and sending an update message including the update data set. 3. The computer system of claim 1, wherein the first data set and the second data set include dynamic data elements that change over time. 4. The computer system of claim 1, wherein the second data set is a subsequent version of the first data set. 5. The computer system of claim 1, wherein the selector selects an operator based on a relationship between a first counter associated with a first data set and a second counter associated with a second data set. 6. The computer system of claim 1, wherein each data element includes a key and a data portion. 7. An electronic transaction system comprising the computer system according to claim 1. 8. A method for generating an updated data set to be sent to a remote terminal, said updated data set comprising an operation describing the difference between a first data set comprising classified data elements and a second data set comprising classified data elements operator, said operator is determined from the group comprising the following operators: add operator, delete operator, replace operator, said method comprising the following steps: - sequentially comparing data elements in the first data set with data elements in the second data set, wherein the result of the first comparison between a data element in the second data set and a data element in the first data set controls which data element in the first data set is compared with which data element in the second data set in the second comparison in this data element comparison order, - After each comparison, the change parameter is updated in the memory, wherein the change parameter includes a first counter related to the first data set and a second counter related to the second data set, and also includes a counter related to the first data set the first positional parameter associated with the set and the second positional parameter associated with the second data set, - in case of detection that a data element in the second data set coincides with a data element in the first data set, initiating a selection process which determines an operator on the basis of variation parameters stored in memory, - storing the determined operator in memory, An updated data set is thereby generated to be sent to the remote terminal, the updated data set comprising an operator describing the difference between the first data set and the second data set. 9. The method of claim 8, further comprising the step of associating the determined operator with the compared data elements. 10. The method of claim 8, further comprising the step of determining an operator based on a relationship between a first counter associated with a first data set and a second counter associated with a second data set. 11. The method of claim 8, wherein each data element comprises a key and a data part, the method further comprising combining the key and data part of the data elements of the first data set with the keys and data parts of the data elements of the second data set Data sections are compared separately. 12. The method of claim 8, wherein the first data set and the second data set include dynamic information that changes over time.

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